Dasha Kovalenko
Robin Wirz
Peter Ocean
Gawain Moody
( Old sampling method)
Null hypothesis There will not be measurable/significant difference between the phenotypes (polymorphisms) of the snail populations, which will not provide evidence for gene flow or the existence of hybrid zones.
Alternative hypothesis There will be a measurable/significant difference between the phenotypes (polymorphisms) of the populations, which will provide evidence for gene flow or hybrid zones.
Reasons for sampling points & expected results Site 1 This site will act as a “control” of sort, as it is isolated from all the other sites. It should not exhibit any gene flow/hybridization, and will show only one phenotype.
Sites 2 - 4 These will show a change in phenotype. There is a possibility of a hybrid zone at site 3, as it is between two separate environments, and gene flow may occur between them.
Sites 5 - 6 These will act experimentally similarly to sites 2- 4. We expect to see a hybrid zone at site 6 between the shrub and the grass.
We will sample all sites (with the exception of site 1 which will act as a control) at a similar altitude in order to minimize the effect of environmental interaction. Although its effect cannot be fully removed, one must take this into account when studying gene flow.
We sampled both the bushland and shrub areas in order to see the variety of phenotypes, to see whether hybrid zones are present, and whether gene flow occurs.
(New file) -_-_-_-_-_-_-_-_-_-_
Snail Trip Sampling plan (revised)09/10/14
Introduction/Abstract
The aim of this experiment/field trip is to observe and record the phenotypes of snails (Cepaea Nemoralis) in an environment. Sampling will then occur in small subdivisions and micro regions within this environment, taking into account many factors, both environmental and physical/genetic.
This will be done in order to study polymorphisms within this area, and to determine what the underlying cause of these of these polymorphisms. The most commonly accepted underlying causes of polymorphisms are :
1.) Mutation – often described as the origin of Polymorphisms
2.) Genetic drift and Mutation – spread/loss within a population
3.) Gene flow – movement from population to another
Hypotheses
Null Hypothesis (H0):There will not be measurable/significant difference between the phenotypes (polymorphisms) of the snail populations, which will not provide evidence for gene flow or the existence of hybrid zones. Alternative Hypothesis (H1): There will be a measurable/significant difference between the phenotypes (polymorphisms) of the populations, which will provide evidence for gene flow or hybrid zones.
Sampling areas & justifications
1-3.) These are being sampled as a transition zone, so that any changes in phenotype may be observed, and so that one can ascertain whether gene flow is occurring in this sampling area. There is potential for a hybrid zone to be formed in sampling box 2, as it is in between 2 different environments, and gene flow may occur between these 2 areas (woodland and grassland).
4-6.) The same line of reasoning as samples 1-3 apply here, however the other environment being sampled is shrub, rather than woodland, and a different phenotype is expected in this area. Another potential hybrid zone is expected in sampling points 4/5.
Points 3 and 6 will act as “controls” due to them being in very similar heights, as well as similar environments (grassland). Minimal gene flow is expected in these areas, and should exhibit 1 phenotype in majority, with perhaps very few other phenotypes. The sampling distance between each point will be kept the same for each set of points (1-3 & 4-6), in order toreduce the number of external factors one has to consider in this investigation such as Height, environmental conditions, Polymorphism’s causes (Mutation, selection, drift,etc.), as whilst they certainly cannot be removed fully, one can minimize their effects.
Both bushland and woodland were sampled in order to observe a variety of phenotypes, and to determine whether hybrid zones are present, and whether Gene Flow affects them.
Limitations
The biggest limiting factors of this investigation are time and environmental interaction with the sampling. Were there more time at hand for the field trip/sampling, a better plan could have been designed, which would bring more indicative and representative results with it.
As mentioned in the previous section, not much can be done for the effect of environmental interactions with the sampling. However, with the little time at our team’s disposal, the modifications to the protocol, such as sampling from the same height and in equidistance (1-3 and 4-6) means that the effects will be greatly diminished.
-_-_-
Experimental method#3 Introduction/Abstract
The aim of this experiment/field trip is to observe and record the phenotypes of snails (Cepaea Nemoralis) in an environment. Sampling will then occur in small subdivisions and micro regions within this environment, taking into account many factors, both environmental and physical/genetic.
This will be done in order to study polymorphisms within this area, and to determine what the underlying cause of these of these polymorphisms. The most commonly accepted underlying causes of polymorphisms are :
1.) Mutation – often described as the origin of Polymorphisms
2.) Genetic drift and Mutation – spread/loss within a population
3.) Gene flow – movement from population to another
Hypotheses
Null Hypothesis (H0): the phenotype ratios/polymorphisms are constant across transition zones. Alternative Hypothesis (H1): the phenotype ratios vary across transitions zones.
Sampling areas & justifications
We chose to take Prof. Nichols' advice on reigning in our ambitions for this project, and not tyring to cover too many variables, as that would skew the objective of this research project.
1-3.) These are being sampled as a transition zone, so that any changes in phenotype may be observed, and so that one can ascertain whether gene flow is occurring in this sampling area. There is potential for a hybrid zone to be formed in sampling box 2, as it is in between 2 different environments, and gene flow may occur between these 2 areas (woodland and grassland).
4-6.) The same line of reasoning as samples 1-3 apply here, however the other environment being sampled is shrub, rather than woodland, and a different phenotype is expected in this area. Another potential hybrid zone is expected in sampling points 4/5.
Points 3 and 6 will act as “controls” due to them being in very similar heights, as well as similar environments (grassland). Minimal gene flow is expected in these areas, and should exhibit 1 phenotype in majority, with perhaps very few other phenotypes. The sampling distance between each point will be kept the same for each set of points (1-3 & 4-6), in order toreduce the number of external factors one has to consider in this investigation such as Height, environmental conditions, Polymorphism’s causes (Mutation, selection, drift,etc.), as whilst they certainly cannot be removed fully, one can minimize their effects.
Both bushland and woodland were sampled in order to observe a variety of phenotypes, and to determine whether hybrid zones are present, and whether Gene Flow affects them.
Limitations
The biggest limiting factors of this investigation are time and environmental interaction with the sampling. Were there more time at hand for the field trip/sampling, a better plan could have been designed, which would bring more indicative and representative results with it. In order to somewhat neutralize these limitations one could pair up with another group which has different experimental design in order to prove/disprove our results using a different approach.
As mentioned in the previous section, not much can be done for the effect of environmental interactions with the sampling. However, with the little time at our team’s disposal, the modifications to the protocol, such as sampling from the same height and in equidistance (1-3 and 4-6) means that the effects will be greatly diminished. Another great limitation is that in order to get a scope of what the sampling area is like, one must actually be on site, hence the experimental design could be altered to accomodate any unforseen changes in the sampling environment/ to make it more appropriate.
The aim of this experiment is to observe the determining forces that direct natural selection, and evolution by proxy, of an air-breathing land-snail called Cepaea nemoralis. This work would represent, to an extent, the underlying forces to natural selection itself, how they interact with one another and how they ultimately affect the polymorphic evolution and distribution of C. nemoralis. The forces that will be taken under close scrutiny are genetic drift and gene flow. Genetic drift is defined as the change in allele frequency in a given population due to random sampling. It is a continuously occurring process due to the fact that it is dependent on the presence of singular organisms. In contrast, Gene flow, which is the transfer of alleles or entire genes from one population to next, is dependent on more than one population interacting with one another. When put into context with natural selection, it can be said that genetic drift occurs in the ‘background’ and is completely independent to it, whilst gene flow is a selection-dependent process. Any given diploid organism can have two or more different alleles designated for one specific gene locus. This allelic pair, or this gene, is what then controls the phenotypic trait associated to it, though it must be said that such correlations are seldom linear. The consequent genetic variety is termed polymorphism, and is the foundation upon which natural selection can act. Natural selection, as defined by Charles Darwin himself, is the evolutionary drive by which each slight variation of a trait of an organism, if useful, is preserved when interacting with the environment (Darwin, 61). Previous studies done on C. nemoralis such as the review paper by Jones et al, have indicated that polymorphism in this organism is a complex phenomenon whose analyses reveal contrasting and overlapping results in a non-linear relationship (Jones et al, “Polymorphism in Cepaea; A Problem with too many solutions?”). Considering that C. nemoralis is what could be called a model organism in this field of study, it can be anticipated that for other organisms with much more complex behavioral patterns, the interactions between these principles would be nigh impossible to predict reliably. References:
GENE-IUSES
Group 14
Dasha Kovalenko
Robin Wirz
Peter Ocean
Gawain Moody
( Old sampling method)
Null hypothesis
There will not be measurable/significant difference between the phenotypes (polymorphisms) of the snail populations, which will not provide evidence for gene flow or the existence of hybrid zones.
Alternative hypothesis
There will be a measurable/significant difference between the phenotypes (polymorphisms) of the populations, which will provide evidence for gene flow or hybrid zones.
Reasons for sampling points & expected results
Site 1 This site will act as a “control” of sort, as it is isolated from all the other sites. It should not exhibit any gene flow/hybridization, and will show only one phenotype.
Sites 2 - 4 These will show a change in phenotype. There is a possibility of a hybrid zone at site 3, as it is between two separate environments, and gene flow may occur between them.
Sites 5 - 6 These will act experimentally similarly to sites 2- 4. We expect to see a hybrid zone at site 6 between the shrub and the grass.
We will sample all sites (with the exception of site 1 which will act as a control) at a similar altitude in order to minimize the effect of environmental interaction. Although its effect cannot be fully removed, one must take this into account when studying gene flow.
We sampled both the bushland and shrub areas in order to see the variety of phenotypes, to see whether hybrid zones are present, and whether gene flow occurs.
(New file) -_-_-_-_-_-_-_-_-_-_
Snail Trip Sampling plan (revised) 09/10/14
Introduction/Abstract
The aim of this experiment/field trip is to observe and record the phenotypes of snails (Cepaea Nemoralis) in an environment. Sampling will then occur in small subdivisions and micro regions within this environment, taking into account many factors, both environmental and physical/genetic.
This will be done in order to study polymorphisms within this area, and to determine what the underlying cause of these of these polymorphisms. The most commonly accepted underlying causes of polymorphisms are :
1.) Mutation – often described as the origin of Polymorphisms
2.) Genetic drift and Mutation – spread/loss within a population
3.) Gene flow – movement from population to another
Hypotheses
Null Hypothesis (H0): There will not be measurable/significant difference between the phenotypes (polymorphisms) of the snail populations, which will not provide evidence for gene flow or the existence of hybrid zones.
Alternative Hypothesis (H1): There will be a measurable/significant difference between the phenotypes (polymorphisms) of the populations, which will provide evidence for gene flow or hybrid zones.
Sampling areas & justifications
1-3.) These are being sampled as a transition zone, so that any changes in phenotype may be observed, and so that one can ascertain whether gene flow is occurring in this sampling area. There is potential for a hybrid zone to be formed in sampling box 2, as it is in between 2 different environments, and gene flow may occur between these 2 areas (woodland and grassland).
4-6.) The same line of reasoning as samples 1-3 apply here, however the other environment being sampled is shrub, rather than woodland, and a different phenotype is expected in this area. Another potential hybrid zone is expected in sampling points 4/5.
Points 3 and 6 will act as “controls” due to them being in very similar heights, as well as similar environments (grassland). Minimal gene flow is expected in these areas, and should exhibit 1 phenotype in majority, with perhaps very few other phenotypes. The sampling distance between each point will be kept the same for each set of points (1-3 & 4-6), in order toreduce the number of external factors one has to consider in this investigation such as Height, environmental conditions, Polymorphism’s causes (Mutation, selection, drift,etc.), as whilst they certainly cannot be removed fully, one can minimize their effects.
Both bushland and woodland were sampled in order to observe a variety of phenotypes, and to determine whether hybrid zones are present, and whether Gene Flow affects them.
Limitations
The biggest limiting factors of this investigation are time and environmental interaction with the sampling. Were there more time at hand for the field trip/sampling, a better plan could have been designed, which would bring more indicative and representative results with it.
As mentioned in the previous section, not much can be done for the effect of environmental interactions with the sampling. However, with the little time at our team’s disposal, the modifications to the protocol, such as sampling from the same height and in equidistance (1-3 and 4-6) means that the effects will be greatly diminished.
-_-_-
Experimental method #3
Introduction/Abstract
The aim of this experiment/field trip is to observe and record the phenotypes of snails (Cepaea Nemoralis) in an environment. Sampling will then occur in small subdivisions and micro regions within this environment, taking into account many factors, both environmental and physical/genetic.
This will be done in order to study polymorphisms within this area, and to determine what the underlying cause of these of these polymorphisms. The most commonly accepted underlying causes of polymorphisms are :
1.) Mutation – often described as the origin of Polymorphisms
2.) Genetic drift and Mutation – spread/loss within a population
3.) Gene flow – movement from population to another
Hypotheses
Null Hypothesis (H0): the phenotype ratios/polymorphisms are constant across transition zones.
Alternative Hypothesis (H1): the phenotype ratios vary across transitions zones.
Sampling areas & justifications
We chose to take Prof. Nichols' advice on reigning in our ambitions for this project, and not tyring to cover too many variables, as that would skew the objective of this research project.
1-3.) These are being sampled as a transition zone, so that any changes in phenotype may be observed, and so that one can ascertain whether gene flow is occurring in this sampling area. There is potential for a hybrid zone to be formed in sampling box 2, as it is in between 2 different environments, and gene flow may occur between these 2 areas (woodland and grassland).
4-6.) The same line of reasoning as samples 1-3 apply here, however the other environment being sampled is shrub, rather than woodland, and a different phenotype is expected in this area. Another potential hybrid zone is expected in sampling points 4/5.
Points 3 and 6 will act as “controls” due to them being in very similar heights, as well as similar environments (grassland). Minimal gene flow is expected in these areas, and should exhibit 1 phenotype in majority, with perhaps very few other phenotypes. The sampling distance between each point will be kept the same for each set of points (1-3 & 4-6), in order toreduce the number of external factors one has to consider in this investigation such as Height, environmental conditions, Polymorphism’s causes (Mutation, selection, drift,etc.), as whilst they certainly cannot be removed fully, one can minimize their effects.
Both bushland and woodland were sampled in order to observe a variety of phenotypes, and to determine whether hybrid zones are present, and whether Gene Flow affects them.
Limitations
The biggest limiting factors of this investigation are time and environmental interaction with the sampling. Were there more time at hand for the field trip/sampling, a better plan could have been designed, which would bring more indicative and representative results with it. In order to somewhat neutralize these limitations one could pair up with another group which has different experimental design in order to prove/disprove our results using a different approach.
As mentioned in the previous section, not much can be done for the effect of environmental interactions with the sampling. However, with the little time at our team’s disposal, the modifications to the protocol, such as sampling from the same height and in equidistance (1-3 and 4-6) means that the effects will be greatly diminished. Another great limitation is that in order to get a scope of what the sampling area is like, one must actually be on site, hence the experimental design could be altered to accomodate any unforseen changes in the sampling environment/ to make it more appropriate.
Date: 11/11/2014
INTRODUCTION; Draft #1.
or Text version:
>>>>BEGINNING<<<<
The aim of this experiment is to observe the determining forces that direct natural selection, and evolution by proxy, of an air-breathing land-snail called Cepaea nemoralis. This work would represent, to an extent, the underlying forces to natural selection itself, how they interact with one another and how they ultimately affect the polymorphic evolution and distribution of C. nemoralis.
The forces that will be taken under close scrutiny are genetic drift and gene flow. Genetic drift is defined as the change in allele frequency in a given population due to random sampling. It is a continuously occurring process due to the fact that it is dependent on the presence of singular organisms. In contrast, Gene flow, which is the transfer of alleles or entire genes from one population to next, is dependent on more than one population interacting with one another. When put into context with natural selection, it can be said that genetic drift occurs in the ‘background’ and is completely independent to it, whilst gene flow is a selection-dependent process.
Any given diploid organism can have two or more different alleles designated for one specific gene locus. This allelic pair, or this gene, is what then controls the phenotypic trait associated to it, though it must be said that such correlations are seldom linear. The consequent genetic variety is termed polymorphism, and is the foundation upon which natural selection can act. Natural selection, as defined by Charles Darwin himself, is the evolutionary drive by which each slight variation of a trait of an organism, if useful, is preserved when interacting with the environment (Darwin, 61).
Previous studies done on C. nemoralis such as the review paper by Jones et al, have indicated that polymorphism in this organism is a complex phenomenon whose analyses reveal contrasting and overlapping results in a non-linear relationship (Jones et al, “Polymorphism in Cepaea; A Problem with too many solutions?”). Considering that C. nemoralis is what could be called a model organism in this field of study, it can be anticipated that for other organisms with much more complex behavioral patterns, the interactions between these principles would be nigh impossible to predict reliably.
References:
Bibliography:
1. Darwin, Charles R., and John Van Wyhe. "On the Origin of Species by Means of Natural Selection..." Darwin-online.org.uk. N.p., 2002. Web. 11 Nov. 2014. <http://darwin-online.org.uk/content/frameset?itemID=F373&viewtype=side&pageseq=76>.
2. Jones, J. S., B. H. Leith, and P. Rawlings. "Polymorphism in Cepaea: A Problem with Too Many Solutions?" Annual Review of Ecology and Systematics 8.1 (1977): 109-43. Web. 11 Nov. 2014. <http://www.annualreviews.org/doi/abs/10.1146%2Fannurev.es.08.110177.000545>.
>>>>END<<<<